Isotropic resistor protect etch to aid in residue removal

摘要

Various methods of fabricating a circuit structure, such as a gate electrode or a resistor are provided. In one aspect, a method of fabricating a circuit structure is provided that includes forming a silicon structure on a substrate and forming an oxide film on the silicon structure. A first portion of the oxide film is masked while a second portion is left unmasked. The second portion of the oxide film is removed by isotropic plasma etching to expose a portion of the silicon structure, and the first portion of the oxide film is unmasked. Use of isotropic etching for removal of a resistor protect oxide reduces the potential for isolation structure damage due to aggressive overetching associated with conventional anisotropic etching techniques.